Each command in a pipeline is executed in its own Subshell(see section Command Execution Environment).
0
2
If a command is terminated by the control operator'&',
the shell executes the command asynchronously in a Subshell.
0
3
If a command is terminated by the control operator ampersand('&'),
the shell shall execute the command asynchronously in a Subshell.
0
4
In addition to the creation of a Subshell, there is a subtle difference between these two constructs due to historical reasons.
0
5
This option applies to the shell environment and each Subshell environment separately see Command Execution Environment,
and may cause Subshells to exit before executing all the commands in the Subshell.
0
6
Placing a list of commands between parentheses causes a Subshell environment to be created(see Command Execution Environment),
and each of the commands in list to be executed in that Subshell.